Because low-abundance arginine-rich DPRs may not be detectable in all patient-derived iPSC lines, we next validated our findings in tissue lysates from human C9-ALS postmortem cerebellum and C9orf72 mutant BAC transgenic mouse striatum (Table S3), using optimized parameters from our initial optimization assays. The gene discussed is C9; the disease is amyotrophic lateral sclerosis.